The Laparoscopic Gastric Bypass Roux-en-Y

The Gastric Bypass Roux-en-Y, also simply known as the Gastric Bypass, is considered the gold standard of weight loss surgery by the American Society of Bariatric Surgeons and the National Institutes of Health. Studies show that the Gastric Bypass helps many patients lose about 75% of their excess weight and maintain the weight loss for years after surgery. Now with modern refinement of the operation, there are many patients losing 85% to 100% of their excess weight and keeping it off.

Click here to view an illustration of incisions for Laparoscopic Weight Loss Surgery.

Click here to view an illustration of incisions for Open Weight Loss Surgery.

Click here to view an illustration of the Gastric Bypass Surgery.

Click here to view an animation of the surgery.

The Procedure
In a Laparoscopic Gastric Bypass surgery, stapling creates a small stomach pouch at the very top of the stomach just below the esophagus, restricting the amount of food a patient can eat. The remainder of the stomach is not removed, but is completely stapled shut and divided from the new pouch. Then, the small intestine is divided at the beginning of the jejunum - the middle section of the small intestine. The jejunum is then brought up and attached to the pouch so that food empties directly into it without the normal digestive juices, so calories and nutrients are less completely absorbed. The end of the duodenum, the first section of small intestine, is then reattached downstream from the pouch.

The normal digestive juices from the stomach, liver and pancreas are now mixed with the food for digestion. This section of jejunum from the new pouch to the duodenum is the bypass – named because it bypasses the old stomach and digestive juices.

Clinical studies show the new, smaller pouch contributes greatly to higher overall weight loss success and long-term weight control.

Why the Procedure Works
The smaller stomach pouch now holds about 15cc, or less than an ounce of food in the beginning. This restricts food intake and the body mostly burns fat for everyday energy. The smaller pouch also creates an early sense of fullness, even after eating less than an ounce. As a result, you will fill satisfied and feel less desire to eat.

Weight loss with the Laparoscopic Gastric Bypass is the greatest in the first 12 months. After a few months, the pouch will continue to expand until it can hold what is necessary to maintain a healthy weight.

Because normal digestive juices are not present, the bypass does not tolerate food with fats, sugars and starches well. A phenomenon known as 'dumping' occurs when these 'unhealthy' foods are eaten in large quantities or without eating enough protein at the same time. Dumping causes a rapid heart rate, nausea, sweating, and a general feeling of illness.

As uncomfortable as this side effect is, this physically reinforced behavior modification actually works in your favor – promoting healthy post-surgery eating behavior.

The Laparoscopic Gastric Bypass is a powerful tool in the journey to successful weight loss. In order for this procedure to work in the long term however, you must be committed to changing your lifestyle completely – eating less, maintaining proper nutrition and exercising regularly.

Possible Risks and Complications
As you make a decision to undergo a laparaoscopic Gastric Bypass, you need to consider not only the positive things it can do for you but also the risks. Please study these carefully. These risks and complications can include:

  • Pulmonary Embolism A pulmonary embolus usually comes from a deep venous thrombosis or blood clot that forms in the veins of the pelvis. A part of the blood clot breaks away and goes up to the lungs, blocking the blood returning to the heart. It can be fatal but occurs in less than 1% of patients who have weight loss surgery.

Before surgery, we take every medical precaution possible to help prevent blood clots. First, when you are being prepped an hour prior to surgery, we treat you with a blood thinner that guards against clotting. Second, you are fitted with pulse stockings for your legs that pneumatically 'squeeze' the blood vessels in your legs – actually 'bruising' your blood and helping to prevent clotting. Third, we get you out of bed four or five hours after surgery and make you walk. Except for about six hours in the middle of the night for sleep, you will be required to walk every two hours for your entire stay in the hospital. This is very important. To help avoid a pulmonary embolism, you need to walk as much as you can while you are in the hospital and when you return home.

These precautions are meant to minimize your risk of a pulmonary embolism, but it can still occur in rare cases.

  • Blockage at a Site Where Tissue Is Stapled or Sewn Together Blockage only occurs in about 2.5% of patients. When it does occur, it is usually caused by tissue swollen by surgery. Normally, this internal swelling will go down and doesn't require re-operation. In rare cases, the patient will need to be re-operated on to open a blockage.
  • Leakage From a Staple Line When leakage occurs, it will usually be within the first week of post surgery. We test the staple line twice: once in the operating room and once the morning after surgery. We also leave a small drain in the area to catch any fluid that leaks out. This complication occurs in 1-4% of the patients who have weight loss surgery.
  • Pneumonia This is an infection in the lungs resulting from collapsed air sacks. It occurs in less than 1% of patients. Patients must work hard on their walking, breathing and coughing exercises after surgery to help prevent pneumonia.
  • Infection An infection can occur in the midline open wound about 12% of the time and in the small puncture sites from laparoscopic incisions about 1% of the time. Normally, this doesn't require further surgery and is best handled by opening the wound and letting the fluid drain out. Often times patients mistake decomposing fat for an infection. This is called 'fat necrosis' and creates a clearish liquid similar to pus.
  • Hernia A hernia is an opening in the muscle of your abdomen, which allows the intestines to come out underneath the skin. It appears as a large 'bulge' under the skin. Hernias occur in patients undergoing laparosopic surgery at a very low rate of about 1%. The incidence of hernias is much higher in 'open' versus laparoscopic surgeries.
  • Bleeding The most common problem with bleeding comes from the raw staple lines and occurs very rarely. This blood is passed out of the rectum with the stool. Almost all patients pass a little blood in their first few stools. Patients rarely need a blood transfusion from post-op bleeding, but it can occur. A second type of bleeding comes from bleeding into the abdomen outside of the intestine. This type of bleeding is extremely rare. Patients must stop any anti-inflammatory medications, herbal supplements, vitamins, and aspirin prior to surgery. We will review your medications with you prior to surgery to make sure you have stopped any medications that increase your risk of bleeding.
  • Vomiting Almost all patients experience this complication but it's usually more like 'spitting up' than vomiting. If you begin having a persistent problem with this after surgery, you need to contact the office. Frequent vomiting is usually caused by eating too fast or overeating and not following the Four Rules.
  • Death The approximate risk of death is 0.5% of patients having weight loss surgery in the United States. This means that 1 in 200 patients will die this year having a weight loss procedure.


The health and medical information presented on this web site is for educational purposes only and is not intended as a substitute for medical care. If you have a medical question about any of this information, please consult your family doctor or a health care professional. Every reasonable effort has been made to ensure the accuracy and reliability of the information presented on this web site. The Scottsdale Bariatric Center makes no guarantee or promise, express or implied, as to the accuracy or reliability of the information presented. This information is subject to change without notice and cannot be guaranteed to be current.